cc-byRodríguezV BartholomäusA WitzgallK Riveras-MuñozN OsesR LiebnerS KallmeyerJ RachO MuellerCW SeguelO ScholtenT WagnerD2025-06-052025-06-05https://hdl.handle.net/20.500.12740/22671The microbiota is attributed to be important for initial soil formation under extreme climate conditions, but experimental evidence for its relevance is scarce. To fill this gap, we investigated the impact of in situ microbial communities and their interrelationship with biocrust and plants compared to abiotic controls on soil formation in initial arid and semiarid soils. Additionally, we assessed the response of bacterial communities to climate change. Topsoil and subsoil samples from arid and semiarid sites in the Chilean Coastal Cordillera were incubated for 16 weeks under diurnal temperature and moisture variations to simulate humid climate conditions as part of a climate change scenario. Our findings indicate that microorganism-plant interaction intensified aggregate formation and stabilized soil structure, facilitating initial soil formation. Interestingly, microorganisms alone or in conjunction with biocrust showed no discernible patterns compared to abiotic controls, potentially due to water-masking effects. Arid soils displayed reduced bacterial diversity and developed a new community structure dominated by Proteobacteria, Actinobacteriota, and Planctomycetota, while semiarid soils maintained a consistently dominant community of Acidobacteriota and Proteobacteria. This highlighted a sensitive and specialized bacterial community in arid soils, while semiarid soils exhibited a more complex and stable community. We conclude that microorganism-plant interaction has measurable impacts on initial soil formation in arid and semiarid regions on short time scales under climate change. Additionally, we propose that soil and climate legacies are decisive for the present soil microbial community structure and interactions, future soil development, and microbial responses. C1 [Rodriguez, Victoria; Bartholomaeus, Alexander; Liebner, Susanne; Kallmeyer, Jens; Wagner, Dirk] GFZ German Res Ctr Geosci, Sect Geomicrobiol, Potsdam, Germany. [Witzgall, Kristina] Tech Univ Munich, TUM Sch Life Sci, Soil Sci, Freising Weihenstephan, Germany. [Riveras-Munoz, Nicolas; Scholten, Thomas] Univ Tubingen, Dept Geosci Soil Sci & Geomorphol, Tubingen, Germany. [Oses, Romulo] Univ Atacama, Ctr Reg Invest & Desarrollo Sustentable Atacama CR, Copiapo, Chile. [Liebner, Susanne] Univ Potsdam, Inst Biochem & Biol, Potsdam, Germany. [Rach, Oliver] GFZ German Res Ctr Geosci, Sect Geomorphol, Potsdam, Germany. [Mueller, Carsten W.] Tech Univ Berlin, Chair Soil Sci, Inst Ecol, D-10587 Berlin, Germany. [Mueller, Carsten W.] Univ Copenhagen, Dept Geosci & Nat Resource Management, Copenhagen, Denmark. [Seguel, Oscar] Univ Chile, Fac Ciencias Agron, Santiago, Chile. [Wagner, Dirk] Univ Potsdam, Inst Geosci, Potsdam, Germany. C3 Helmholtz Association; Helmholtz-Center Potsdam GFZ German Research Center for Geosciences; Technical University of Munich; Eberhard Karls University of Tubingen; Universidad de Atacama; University of Potsdam; Helmholtz Association; Helmholtz-Center Potsdam GFZ German Research Center for Geosciences; Technical University of Berlin; University of Copenhagen; Universidad de Chile; University of Potsdaminfo:eu-repo/semantics/openAccessarid soilsemiarid soilmanipulation experimentclimate changeinitial soil formationbacterial communityMicrobiologyArticulo de revista10.3389/fmicb.2024.1319997